# CVE-2026-71227: Libkcapi: infinite loop denial of service in libkcapi _kcapi_aio_read_all() due to unhandled io_getevents() timeout return

Status: published. Published: 2026-08-05. Updated: 2026-11-02.

A flaw was found in libkcapi. A local attacker can influence an application that uses the Asynchronous Input/Output (AIO) interface. By reusing an AIO-enabled handle after a prior completion error, the _kcapi_aio_read_all() function can enter a non-terminating wait loop. This can lead to a persistent denial of service, making the affected application or thread unresponsive.

## Remediation

- workaround: To mitigate this issue, applications should avoid initializing `libkcapi` handles with `KCAPI_INIT_AIO` if AIO functionality is not strictly required. If AIO must be used, applications should destroy and reinitialize `libkcapi` handles after any AIO completion error, rather than reusing them for subsequent AIO operations. (source: CNA: redhat)

## Affected products and versions

- Stephan Muelle / libkcapi: ≥ 0.12.0; < 1.5.1 (affected, semver). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (libkcapi): ≥ 0:1.5.1-1.el10_2; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10.0 Extended Update Support (libkcapi): ≥ 0:1.5.0-6.el10_0; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (libkcapi): ≥ 0:1.4.0-3.el8_10; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (libkcapi): ≥ 0:1.4.0-3.el9_8; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9.6 Extended Update Support (libkcapi): ≥ 0:1.4.0-2.el9_6.1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (libkcapi-main): ≥ 1.5.1-0.1.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5.1 (medium); CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.20% as of 2026-11-01; percentile 9.46%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-835

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:56985 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:67265 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:67266 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:67267 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:69285 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:87712 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-71227 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2462867 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-71227; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-71227; retrieved 2026-11-02; source updated Not reported

Revision: 3131f0de7141fa959a6444857dd70bc5616fedb92b845b85df1bc47b00e2ea47

Canonical: https://y2.dev/cve/CVE-2026-71227